Editor's Note: Acoustic neuromas are non-cancerous tumors found in the brain and are accompanied by hearing loss and tinnitus. You can read more about the nature of Acoustic Neuromas in our Tinnitus Information Center.

Do Cell Phones Cause Acoustic Neuroma?

by Barry Keate

There has been a good deal of discussion in scientific circles recently over the concern that radio-frequency (RF) radiation, from cell phone usage, may cause damage to the human brain in the form of an acoustic neuroma.

The incidence of acoustic neuroma among tinnitus patients is approximately one in one thousand individuals as opposed to one in one hundred thousand in the general population. This is the reason many ENT physicians require an MRI of their tinnitus patients; to rule out the possibility of acoustic neuroma.

One of the primary symptoms is hearing loss and tinnitus, usually occurring in only one ear. Acoustic neuromas are rare, non-malignant growths that occur on the auditory nerve leading from the cochlea to the brain. They are slow growing, developing over many years, and are not cancerous. They do not spread but continue growing from the point where they begin.

They can be very dangerous, however, if left undiagnosed. As they grow they may begin to press against the brain, causing pressure on the brainstem and endangering vital functions necessary to life.

In 2003, a study was published that showed microwave radiation emitted from GSM (digital) mobile phones caused damage to the brains of laboratory rats. Leif Salford and colleagues at Lund University Hospital in Lund, Sweden attached cell phones to the cages of rats and varied the intensity of radiation to reflect the range of exposures a human cell phone user might experience over the same time period. They exposed the rats to this radiation for two hours.

Fifty days after the one-time, two-hour exposure, the rats’ brains showed significant blood vessel leakage as well as areas of shrunken, damaged neurons. The higher the radiation exposure, the more damage was apparent. 1

The safety of cell phone usage was first brought to the public’s attention in a 2003 lawsuit filed in the death of a Florida woman by her husband. He claimed that the cell phone he bought for her when she was pregnant caused or accelerated the growth of the brain tumor that killed her. The case was later dismissed for lack of scientific evidence but the media had hold of it by then and started raising questions.

Hand-held phones appear to be the most damaging. Phones mounted in cars, with the antenna outside, appear safe. Using a headphone that allows the individual to hold the main power source away from their head is also preferable.

Network news programs ran their own tests of mobile phones and found that some exceed the maximum level of emitted radio-frequency energy allowed by the US Federal Communications Commission (FCC).

In 2004 a landmark study was completed at the prestigious Karolinska Institute in Stockholm, Sweden on the use of cell phones and acoustic neuroma. The study, published in Epidemiology, provided conclusive proof that use of cell phones over a 10 year period significantly increased the user’s chance of developing acoustic neuroma. It showed there was no increased incidence of the tumor within 10 years but that after that time the risk increased two-fold. When tumors appearing on the same side of the head as used for cell phones were compared, the risk increased four-fold. 2

Researchers said they found no association between the tumors and the amount of use measured in hours or cumulative number of calls but rather on the length of time those in the study had been regular users of cell phones.

“It is a natural place to look for a problem because this is the area of the head that is exposed” said Anders Ahlbom, director of the Institute of Environmental Medicine at the Karolinska Institute.

Dr. Henry Lai, research professor of bioengineering at the University of Washington in Seattle, WA said the Karolinska study is not the first to show a link between cell phones and acoustic neuroma. “Another Swedish researcher, Dr. Lennart Hardell found similar results in 2002, so this is, in effect, a replication. I think the data is quite solid and is cause for concern on long-term cell phone use.” 3

Dr. Sam Milham, epidemiologist and pioneer in studying the effects of electromagnetic radiation on humans, said it usually takes 20 years or more for solid tumors to develop. “I’m actually astonished that they found anything like this early,” Milham stated in an article published in Florida's Sun-Sentinel. “If that energy can do that to normal nerve tissue cells, what can it do to adjacent brain cells? I think it’s the tip of a big iceberg and the peak could be 25 years past exposure. What’s really alarming is that in the last five years an enormous number of people started using cell phones, including kids, so I think this is just the beginning of it. I hope I’m wrong.”

At least three federal agencies, the Food and Drug Administration (FDA), the Federal Communications Commission (FCC) and the Environmental Protection Agency (EPA), have roles in regulating radio-frequency radiation. Only recently has the federal government committed funds to study the cell phone issue. Those studies are not expected to be completed for five to seven years.

In October, 1999, the FDA responded to increased media focus by issuing a Consumer Update on Mobile Phones in which it stated, “The available science does not allow us to conclude that mobile phones are absolutely safe or that they are unsafe. However, the available scientific evidence does not demonstrate any adverse health effects associated with the use of mobile phones.” 4

To be sure, there are clinical studies that show cell phones do not cause acoustic neuroma or other brain tumors. However, the majority of these studies were conducted on users of less than ten years. A study published in the British Journal of Cancer in 2005 is representative of these and states, “The study suggests that there is no substantial risk of acoustic neuroma in the first decade after starting mobile phone use. However, an increase in risk after longer term use or after a longer lag period could not be ruled out.” 5

Those at highest risk of suffering long-term consequences are children, who are now beginning to use cell phones at 8 to 10 years old. Some experts say research conducted in the past decade indicates the world’s 1.6 billion cell phone users are the equivalent of lab rats in a grand living laboratory and that children, with many years of cell phone use ahead of them, might be particularly vulnerable.

In the United Kingdom, Education Secretary David Blunkett has written to all schools in England and Wales. He stated that pupils under 16 years old should not use cell phones except in emergencies. His order to schools follows an investigation by Government chief scientist Sir William Stewart that children could be susceptible to damage from radiation because their immune system is not fully developed. He also pointed out that the younger the child, the more years they could be exposed to radiation.

In 2006, Walt Disney Internet Group, teaming with Sprint, began Disney Mobile to provide cell phones for “the family mobile market.” Disney withdrew cell phone faceplates featuring Mickey Mouse and other cartoon characters when health concerns were raised by cell phone research. Nonetheless, Disney Mobile is today offering cell phones and calling plans to children as young as 8 years old.

How do we protect ourselves and our children from the consequences of long-term exposure? Awareness and moderation are the best courses to follow. Being aware that a potential danger exists can help change our own behaviors and modify ovedrall useage. Until further research resolves this issue, here are some idaeas to reduce exposure to cell phone radiation.

1. Reduce the amount of time spent using cellular phones. Whenever possible, use a land-line.

2. Use a hands-free kit which dramatically reduces the absorption of RF energy in the head.

3. Use the cell phone in speaker-phone mode and hold it in front of you. This is not practical in noisy, public settings but works fine in the home or office.

4. Restrict cell phone use in children and adolescents except in emergency situations.

References:

1. Sanford, L., Brun, A., Eberhardt, J., Malmgren, L., Persson, B. Nerve cell damage in mammalian brain after exposure to microwaves from GSM mobile phones. Environmental Health Perspectives Volume 111, Number 7, June 2003.
2. Lonn S, et al, (2004) Mobil phone use and the risk of acoustic neuroma, Epidemiology, Volume 15, No 6, 653-659, November 2004.
3. Hardell L, Mild KH, Carlberg M, Further aspects on cellular and cordless telephones and brain tumors. Int. J. Oncology, 2003 Feb; 22(2): 399-407.
4. US Food and Drug Administration, Center for Devices and Radiological Health, October 20, 1999.
5. Schoemaker MJ, et al., Mobile phone use and risk of acoustic neuroma: results of the interphone case-control study in five North European countries. Br J Cancer 2005 Oct 3:93(7):842-8.